The present invention relates to novel antitumor drug 4-{p-[bis(2-chloroethyl)amino]phenyl}butyric acid (Chlorambucil) derivatives and a process for producing the same. More particularly, it relates to Chlorambucil derivatives obtained by chemically binding Chlorambucil to hydroxyl group at 17-position of estradiol or its derivative in the presence of a binding agent and antitumor drugs thereof.
As it is well-known, most of antitumor drugs affect to cancer cells and also normal cells and accordingly, they impart serious side effect. Thus, it is difficult to administrate for a long period so as to completely damage cancer cells.
The inventors have studied to overcome such disadvantages of the known antitumor drugs and to develop novel antitumor drugs having high therapeutic effect. As the result, the inventors have succeeded in obtaining novel antitumor estradiol derivatives, which selectively attach certain cancer cells and have low side effect.